Danielle Carter's goal delivered a record 14th Women's FA Cup trophy for Arsenal as they dominated holders Chelsea at Wembley Stadium.
Carter, who clipped a first-minute chance onto the roof of the net, gave the Gunners a deserved early lead with a fine solo run and curled finish.
Asisat Oshoala then spurned three good chances to double Arsenal's lead.
Fran Kirby wasted Chelsea's best opening in front of a record Women's FA Cup final crowd of 32,912.
The England striker lacked direction with her first-half strike after running through, allowing goalkeeper Sari Van Veenendaal to save at the near post.
Ji So-Yun also went close after the break, shooting wide following their first corner after 70 minutes but the Gunners were excellent value for the victory.
Relive Arsenal's victory over Chelsea
Arsenal's greater mobility, movement in midfield and high-pressing was key to their fast start.
Jordan Nobbs, Fara Williams and Carter were key in denying space and stopping the supply line to Chelsea's front four.
Holding duo Katie Chapman and Drew Spence were constantly harassed and crowded out, meaning last year's Wembley matchwinner Ji was starved of possession.
The high-tempo approach set the tone for Arsenal's impressive display and the margin of victory - against a Blues side who had won all seven of their matches so far this season - should have been greater.
Carter's sensational first-half strike was a fitting way to win an intriguing final in front of a record crowd.
Some nimble footwork saw her cut inside Hannah Blundell and send a glorious strike curling into the far post.
But the Gunners wasted numerous chances to avoid a nervy finale.
The most notable opportunities fell to the otherwise excellent Oshoala, who wasted two good chances when through on goal, and Josephine Henning, who headed wide from a corner after the interval.
Ultimately Carter's eye-catching goal was enough but Kelly Smith's contribution was just as vital.
The England legend's inclusion raised a few eyebrows but her composure and quality shone through.
The 37-year-old was increasingly influential, finding and creating space in the centre of the pitch and picking out willing runners time and time again.
At the other end Chelsea's key player Ji, and her fellow attackers Kirby, Karen Carney and Gemma Davison were peripheral figures.
Kirby should have scored when Chelsea had their best spell just after going behind, and Davison made several dangerous runs, but the end product was lacking and Arsenal were not to be denied.